The Proviz switch vest is made from a dual-layer out shell that can be worn either way to give you two options, one for the day and one for night. Depending on which color you choose (yellow or black model) you have great flexibility. By night the reflective material lights up when vehicle headlights are shined upon it enabling the user to be seen more clearly on the roads at night, therefore enabling drivers to adapt accordingly to your position on the road. About the fabrics: the fabrics used for the switch range were chosen specifically to make the switch gilet extremely versatile. The reflective material used is the same as the incredibly popular REFLECT360 range and it is certified to CE EN 20471 standard.